The subject matter disclosed herein relates to a cart support system for dynamoelectric machine coils. More specifically, the subject matter disclosed herein relates to a cart support system for dynamoelectric machine coils that provides clamping means to allow testing of the coils under simulated load conditions.
Dynamoelectric machines such as electrical generators conventionally include a rotor and a stator. The rotor is conventionally provided with field windings (rotor coils) that excite the generator while receiving current from an excitation source. The stator is provided with windings (or coils) from which electrical power is output. At least some known coils/windings are formed with a plurality of copper conductors that are wound to form loops. More specifically, the coils/windings are arranged in such a manner to enable a desired voltage and current characteristic to be generated during operation.
Electrical insulation is wrapped around the rotor coils and stator windings to electrically isolate the coils/windings from subsequent layers. The insulation facilitates preventing arcing between the coils/windings, and also shields the conductors from foreign objects that could cause electrical shorts. However, the insulating properties of the insulation may degrade if the insulation becomes damp or is damaged (e.g., by vibration). Voltage arcs may occur from the conductors through degraded regions or wet regions of the insulation. Over time, continued operation with arcs may prematurely shorten the useful life of the generator.
To facilitate extending the useful life of the generator, the rotor coils and/or stator windings may be periodically tested. Within at least some known tests, groups of stator bars are “tied together” electrically and tested as a set, while the remaining bars are electrically grounded. Rotor coils/windings may be subject to various electrical tests, such as wind copper resistance tests, polarization index tests, AC impedance tests, overpotential tests and air gap flux probe tests. Insulation is used to isolate the various layers of the windings/coils from adjacent layers. If a fault exists in this insulation, damage to the machine could occur or efficiency could be affected. The various tests previously described are performed to identify any fault conditions or defects in the windings/coils before the components are installed in a generator. If defects are discovered, the location can be identified and the problem remedied (e.g., additional insulation is installed in the area of arcing and the test is re-performed). The process may need to be repeated several times before a successful test for the component under test may be performed at the required voltage level.